×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Sizing Discharge pipe

Sizing Discharge pipe

Sizing Discharge pipe

(OP)
We have just had a new plant installed, and are having trouble with a pump. The pump should be capable of 20 tonee/hour, but is doing almost mothing. I think the discharge pipe work may be too small, and is therefore restricting the flow.

Discharge pipework is 1 1/4" with a run of about 15.0 metres. What sort of head will this generate? Is there any reason we can't increase the pipe diameter?  

RE: Sizing Discharge pipe

1 1/4" pipe does sound small for that duty. The head would be about 18 m (assuming you are pumping water) and the velocity would be close to 6 m/s.

But it may have been designed that way deliberately. If you make the discharge pipe larger to decrease the head and increase the flow you may need more power than the motor can deliver - this is called the "run off" condition. You should get hold of the pump curve and see where your operating points (current and desired) are relative to the Best Efficiency Point on the curve. The pump supplier should be able to advise you.

Katmar Software
Engineering & Risk Analysis Software
http://katmarsoftware.com

RE: Sizing Discharge pipe

Is the "Check Valve" installed backwards?

RE: Sizing Discharge pipe

Is the pump running backwards?  That would produce very little flow.

Ted

RE: Sizing Discharge pipe

Check your suction strainer - it may be plugged....and as hydtools said, I'd check rotation right away.  Your pump may also be vapour locked...bleed the discharge to remove casing vapour.

RE: Sizing Discharge pipe


 With 1.1/4 ins discharge you should be flowing 45 GPM if you are pumping water, which equates to approx 10 ton /hr at velocity 10fps with sch 40 pipe.

Offshore Engineering&Design

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources